Basf Aktiengesellschaft

Peter Braune

Thomas Heitz

Martin Jochen Klatt

Herbert Fisch

Helmut Heel

Erich Pellkofer

Georg Schneider

The invention relates to the use of thermoplastic polyester molding compounds, containing A) 80 to 100 wt. % of a polyalkylene arylate, especially polybutyleneterephthalate, with a half-width of crystallization heat releases of &lE;5&deg; C. and B) 0 to 20 wt. % of other additives, the weight percentages of constituents A) and B) adding up to 100%, for producing molded bodies by blow-molding, profile extrusion and/or pipe extrusion. A preferred use for the inventive molding compounds is the production of light guide sheathing. The invention also relates to a 3-stage method for producing the polyesters as follows: a) esterification or re-esterification of an aromatic dicarboxylic acid or its derivative and a glycol; b) precondensation; and c) polycondensation to a viscosity number of at least 158 ml/g. The reaction is carried out in at least 2 temperature zones in stages a) and b).

Use of high-molecular polyester moulding materials

A process for preparing polyalkylene arylates by esterifying or transesterifying an aromatic dicarboxylic acid or its esters or ester-forming derivatives with a molar excess of an aliphatic dihydroxy compound and polycondensing the resultant esterification or transesterification product comprises polycondensing the prepolymer with a viscosity number (VN) of <30 ml/g in the presence of an oxygen-containing gas.

Polyalkylene arylates containing a high proportion of carboxyl end groups

Method of reprocessing residues containing dihydroxy compounds

Continuous preparation of thermoplastic polyesters

Process for preparing residues containing dihydroxy compounds

Thermoplastic polyesters are prepared by multistage polycondensation of dihydroxy compounds with dicarboxylic acids or esters or ester-forming derivatives thereof by a process in which, in at least one first stage, an alkali metal compound or an alkaline earth metal compound is added in an amount of from 1 to 10 mmol, calculated as alkali metal or alkaline earth metal, per kg of polyester, and at least one further stage is carried out as a solid-phase condensation.

Preparation of thermoplastic polyesters

A process for working up residues which contain dihydroxy compounds and are obtained in the preparation of polyesters by reacting dicarboxylic acids or their esters or ester-forming derivatives with dihydroxy compounds,

Working up residues containing dihydroxy compounds

Thermoplastic polyesters are prepared by polycondensation of dihydroxy compounds with dicarboxylic acids or their esters or ester-forming derivatives by a process in which an alkali metal compound or an alkaline earth metal compound is added in an amount of less than 1 mmol, calculated as alkali metal or alkaline earth metal, per kg of polyester.

Growing community of inventors

Erbes-Büdesheim, Germany

Peter Braune